Downstream manoeuvre led to capsizing, NTSB finds

A relief captain’s decision to perform a ‘downstreaming’ manoeuvre in high water conditions resulted in the capsizing and sinking of towing vessel Ricky J Leboeuf on the San Jacinto River just outside of Houston in April 2016, causing the death of one of the five crewmembers, the US National Transportation Safety Board (NTSB) has found.

At 07.52 local time on April 19th 2016, towing vessel Ricky J Leboeuf capsized and later sank while attempting to remove a barge from the Kirby Inland Marine fleeting area in the San Jacinto River near Channelview, Texas. About 10,400 gallons of diesel oil, lubricating oil, and other contaminants were released into the river when the vessel sank.

“The National Transportation Safety Board determines that the probable cause of the capsizing and sinking of the towing vessel Ricky J Leboeuf was the relief captain’s ill-advised decision to perform a downstreaming manoeuvre in high water conditions without implementing the operating company’s risk mitigation strategies or other safeguards,” the NTSB said in its Marine Accident Brief.

The day before, the watershed of the San Jacinto River received more than five inches of rainfall. At the time of the accident the river gauge was at 15ft (major flood stage) and the current was at least 3.5 knots. Due to the severe weather and flooding, the Coast Guard Vessel Traffic Service Houston had issued advisories warning mariners about the hazards.

“These advisories included restrictions on a manoeuvre known in the industry as “downstreaming” and a requirement to use assist towing vessels while operating in barge fleeting areas,” the NTSB report said.

Downstreaming is a procedure in which a towing vessel moves downstream with the current of a river in order to approach and land on another object, such as a barge or a dock. If done correctly, a towing vessel will proceed upstream of the fleet before turning downstream to move toward the fleet, preferably with the engines in reverse to allow the towing vessel to move toward the barges at a slower speed than the current. But too much current can pose significant risk to the towing vessels.

“If the towing vessel meets the barge at an angle and there is a strong-enough current, the towing vessel may be turned sideways and pinned against the barge. A significant risk is present for the towing vessel in this instance. Water may rise up onto the deck and enter into the vessel through open doors, windows, hatches, and ventilation systems, thus causing rapid downflooding, capsizing, and sinking, said the report.

The NTSB said during the investigation its investigators found evidence that Kirby Inland Marine was aware of the risk associated with performing a downstreaming manoeuvre and addressed the risk in its safety management system (SMS). The NTSB said the SMS prohibited the manoeuvre during certain river conditions without permission from the company port captains, among other conditions being met.

The NTSB said the Ricky J Leboeuf sustained an estimated $900,000 in damage, rendering it a constructive total loss.